Vehicular networks and their associated technologies enable an extremely varied plethora of applications and therefore attract increasing attention from a wide audience. However, vehicular networks also have many challenges that arise mainly due to their dynamic and complex environment. Fuzzy Logic, known for its ability to deal with complexity, imprecision, and model non-deterministic problems, is a very promising technology for use in such a dynamic and complex context. This article presents the first comprehensive survey of research on Fuzzy Logic approaches in the context of vehicular networks, and provides fundamental information which enables readers to design their own Fuzzy Logic systems in this context. As such, this article describes the Fuzzy Logic concepts with emphasis on their implementation in vehicular networks, includes classification and thorough analysis of the Fuzzy Logic-based solutions in vehicular networks, and discusses how Fuzzy Logic could be employed in the context of some of the key research directions in the 5G-enabled vehicular networks.